Twenty-four million more Americans would be uninsured by 2026 under the House Republican health care bill than under Obamacare, including 14 million by next year, the non-partisan Congressional Budget Office said Monday.

The long-anticipated score immediately puts the writers and supporters of the GOP Obamacare repeal bill on the defensive. It is also certain to complicate the party’s already troubled efforts to repeal and replace the Affordable Care Act.

The CBO, along with the Joint Committee on Taxation, found that 5 million fewer people would be covered under Medicaid by 2018, and 14 million fewer people would enroll in the program by 2026. Meanwhile, 6 million fewer Americans would be covered in the individual market by 2018, but by 2026, only 2 million fewer people are expected to be covered. That’s in part because fewer employers would offer insurance to their workers, driving more people to the individual market.

In total, an estimated 52 million people would be uninsured by 2026 under the GOP plan, compared to 28 million who would lack insurance under the current law.